Revert of [Sync] Refactor ModelSafeWorker::DoWorkAndWaitUntilDone() to avoid code duplication.

components/password_manager/sync/browser/password_model_worker.cc

Index: components/password_manager/sync/browser/password_model_worker.cc
diff --git a/components/password_manager/sync/browser/password_model_worker.cc b/components/password_manager/sync/browser/password_model_worker.cc
index 997a0b1cbe17168918e95fd2ef162f0713295dbd..81fb889b3b53dfbbfb756cde2a379247fd2e608d 100644
--- a/components/password_manager/sync/browser/password_model_worker.cc
+++ b/components/password_manager/sync/browser/password_model_worker.cc
@@ -4,16 +4,58 @@
 
 #include "components/password_manager/sync/browser/password_model_worker.h"
 
-#include <utility>
-
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/synchronization/waitable_event.h"
 #include "components/password_manager/core/browser/password_store.h"
+#include "components/sync/base/scoped_event_signal.h"
 
 namespace browser_sync {
+
+namespace {
+
+void CallDoWorkAndSignalEvent(const syncer::WorkCallback& work,
+                              syncer::ScopedEventSignal scoped_event_signal,
+                              syncer::SyncerError* error_info) {
+  *error_info = work.Run();
+  // The event in |scoped_event_signal| is signaled at the end of this scope.
+}
+
+}  // namespace
 
 PasswordModelWorker::PasswordModelWorker(
     const scoped_refptr<password_manager::PasswordStore>& password_store)
     : password_store_(password_store) {
   DCHECK(password_store.get());
+}
+
+syncer::SyncerError PasswordModelWorker::DoWorkAndWaitUntilDoneImpl(
+    const syncer::WorkCallback& work) {
+  syncer::SyncerError error = syncer::UNSET;
+
+  // Signaled when the task is deleted, i.e. after it runs or when it is
+  // abandoned.
+  base::WaitableEvent work_done_or_abandoned(
+      base::WaitableEvent::ResetPolicy::AUTOMATIC,
+      base::WaitableEvent::InitialState::NOT_SIGNALED);
+
+  bool scheduled = false;
+  {
+    base::AutoLock lock(password_store_lock_);
+    if (!password_store_.get())
+      return syncer::CANNOT_DO_WORK;
+
+    scheduled = password_store_->ScheduleTask(base::Bind(
+        &CallDoWorkAndSignalEvent, work,
+        base::Passed(syncer::ScopedEventSignal(&work_done_or_abandoned)),
+        &error));
+  }
+
+  if (scheduled)
+    work_done_or_abandoned.Wait();
+  else
+    error = syncer::CANNOT_DO_WORK;
+  return error;
 }
 
 syncer::ModelSafeGroup PasswordModelWorker::GetModelSafeGroup() {
@@ -29,15 +71,6 @@
 
 PasswordModelWorker::~PasswordModelWorker() {}
 
-void PasswordModelWorker::ScheduleWork(base::OnceClosure work) {
-  base::AutoLock lock(password_store_lock_);
-  if (password_store_) {
-    password_store_->ScheduleTask(
-        base::Bind([](base::OnceClosure work) { std::move(work).Run(); },
-                   base::Passed(std::move(work))));
-  }
-}
-
 void PasswordModelWorker::RequestStop() {
   ModelSafeWorker::RequestStop();